1. Technical Field
The present invention relates to integrated circuit packaging, and more particularly to small outline packaging for surface mount integrated circuits.
2. Description of Related Art
Surface mount integrated circuits can be packaged in a Small Outline Package (SOP). An SOP includes Plastic Small Outline Package (PSOP), Thin Small Outline Package (TSOP), Shrink Small Outline Package (SSOP), Thin Shrink Small Outline Package (TSSOP), and Small Outline J-Lead Package (SOJ Package). These Small Outline Packages give users packaging choices for various types of integrated circuit and device applications. For example, SOPs support a wide range of nonvolatile memory component densities and features for user applications.
FIG. 1A illustrates a front elevation of a standard prior art TSOP 100. The TSOP 100 includes a case 102 and gull wing shaped lead-frame (leads) 104. The TSOP 100 may be mounted on a substrate 106, forming a separation 108 between the case 102 and substrate 106. A typical separation 108 is about 0 to 0.1 mm. Unfortunately, it is difficult to fit an additional device between the case 102 and substrate 106 due to the limited size of the separation 108. Further, the gull wing shape of the leads 104 provides an extension 110 from the sides of the case 102. A typical extension 110 is about 0.8 mm. Thus, a total extension 110 on two sides of the TSOP 100 can be about 1.6 mm or more. Such an extension 110 can result in the TSOP 100 occupying a footprint that is substantially greater than the area of the case 102. Thus, the extension 110 of the lead-frame 104 occupies substantial usable area on the substrate 106.
FIG. 1B illustrates a front elevation of a prior art SOJ Package 120. The SOJ Package 120 includes a case 122 and leads 124. The leads 124 are configured in the shape of a “J.” Unfortunately, for similar reasons as discussed above with respect to TSOP 100, it is difficult to fit an additional device under the case 122. Moreover, the curved portion of the J shaped leads 124 complicates mounting to a flat substrate.